The present invention relates to devices for injecting, infusing, delivering, dispensing or administering a substance, and to methods of making and using such devices. More particularly, it relates to an insertion device for insertion heads, an arrangement comprising the insertion device, a use of the insertion device or of the arrangement, and/or a method for applying an insertion head to the body of a patient with the insertion device.
In patients with a regular requirement for a medicament that can be administered by direct delivery into the body tissue or into the blood stream, for example certain groups of patients suffering from pain, or patients with type I and type II diabetes, it can be useful to supply the body with the required quantity of medicament in liquid form via a cannula that is introduced at a suitable location into the body and that remains there over quite a long period of time. For this purpose, a cannula arrangement, designated as an infusion set or port, depending on its design, is secured on the patient's skin, in such a way that the cannula passes through the skin and into the body.
Efforts are also increasingly being made to monitor certain medical parameters of a patient, for example the blood sugar value, continuously over quite a long period of time. For this purpose, a sensor arrangement, for example, is placed on the patient's body and, with a puncturing tip of a suitable sensor, passes through the skin and into the patient's body.
To avoid infections, the infusion set, the port or the sensor arrangement has to be changed at regular intervals, for example every three days. In outpatient treatment, for example in the case of diabetics, this is often done by the patients themselves and, on account of the introduction of the infusion cannula or of the puncturing tip into the skin, is associated with a certain amount of pain. It is therefore important that such infusion sets, ports or sensor arrangements can be applied easily and safely, which is why many manufacturers have started designing their products as insertion heads for special insertion devices with the aid of which the insertion heads can be applied to the patient's body. Application is made easier in this way, and the pain occasioned by the application is reduced to a minimum, thanks to the quick and targeted puncturing procedure.
Thus, for example, U.S. Pat. No. 6,607,509 B2 discloses insertion devices for infusion sets, in which the infusion set is placed abruptly onto the application site by the force of a pretensioned spring, and the cannula penetrates into the tissue of the patient. The insertion device is in this case triggered by actuation of a trigger button that is arranged at one end and that can be locked and unlocked by turning it, or by simultaneous actuation of two radial trigger buttons lying opposite one another.
WO 03/026728 A1 discloses similar insertion devices triggered by pressing two retention arms with locking lugs together or by pressing a trigger button.
WO 2004/110527 A1 also discloses similar insertion devices for infusion sets, in which the triggering is effected by actuation of a single trigger button that is arranged at one end and that can be alternately locked and unlocked by pivoting of a safety lever, or by simultaneous actuation of two trigger buttons lying opposite one another.
All of the above-noted known insertion devices have the disadvantage that they are not secured, or are only inadequately secured, against inadvertent triggering, since any safety devices, if indeed any are present at all, are often not even activated, or are already deactivated before the insertion device is placed on the application site. There is, therefore, considerable danger that a user will accidentally trigger the insertion device and sustain an injury, for example from the infusion cannula of the infusion set that is to be applied, or from the puncturing tip of the sensor arrangement that is to be applied.